Twitter fans are still mourning the "digital deaths" of some of their favorite celebrity tweeters–a handful of celebrities donated their Twitter privileges to raise awareness for HIV/AIDS–but most are alive and tweeting again. This week’s peek into the celebrity world of Twitter reveals wacky costumes, cartoon doppelgangers, and furry friends.

Coldplay’s Chris Martin wore a wig and sunglasses to perform the band’s new holiday single "Christmas Lights" as Elvis on the UK’s show Top of the Pops. "Chris is ready and raring," the band tweeted. Wonder how his wife Gwyneth Paltrow felt about his get-up!

Kim Kardashian posted this pic of her and Katy Perry, who was dressed in a zany Nutcracker costume, backstage at Jingle Ball at Madison Square Garden. "Just bumped into @KatyPerry back stage! LOVE her so much!!!" was her caption. It’s nice to know that even stars get starstruck.

"Bulletproof" singer La Roux posted this pic of a character from the kid’s cartoon Courage the Cowardly Dog. "Now I know where my inspiration comes from," she tweeted, referring to the fiery red hair.

Mariah Carey may be expecting, but it looks like she’s already got two cute babies at home! She tweeted this pic of her and hubby Nick Cannon‘s adorable Jack Russel Terriers with the caption, "Cha Cha + Jackie "L" Chops! Which ones which?? lol"

Does Disney star Selena Gomez think her album cover is so cute that she can just eat it up? No, it’s a cookie in the shape of her album, "A Year Without Rain", that she was given by the caterers at one of her concerts. "How sweet and awkward… Jk, love you Boston!!" she tweeted.

Twitter is great for fashion tips, too, even if they are self-promoting! Designer Rachel Roy posted this pic of herself in one of her own teal Flashdance-style sweatshirts and tweeted "Obsessed with sweatshirts—they make everything look effortless." In an earlier post she told her Twitter followers that the ornate gold necklace she’s wearing is from India.